The increased diversity in the functionality of mobile phones has resulted in an increase in the complexity of the design of these devices. Specifically, for example, increased mobile phone functions such as dual mode (e.g., a combination of an analog mode and a digital mode, or a combination of digital modes, such as TDMA or CDMA), dual band (e.g., a combination of an 800 MHz band and a 1.9 GHz band, or a combination of a 900 MHz band and a 1.8 GHz band or a 1.5 GHz band), and multiple bands (e.g., those previously mentioned plus 3 G UMTS, 4 G LTE) have been increasing the complexity of mobile phone RF architecture and circuitry. Furthermore, constraints on physical space available for the antenna or antennas can limit antenna bandwidth, which is the range of frequencies over which the antenna can operate with acceptable efficiency and power transfer. Conversely, the increased frequency ranges needed for multi-mode phones increase the need for performance over a number of frequency channels, or a wide bandwidth antenna. Moreover, to support these multiple, diverse functions while maintaining proper isolation and reliable signal transfer between transmitter and receiver, present communication devices use multiple sets of fixed circuitry, such as an increased quantity of switches, filters, power amplifiers, and duplexers to customize the device capabilities for each mode of operation. Accordingly, such increased use and quantity of components creates the need for optimizing the performance of the components used as well as different solutions that avoid the proliferation of hardware and provide a more scalable solution
In this regard, there is a continuing demand for component reduction and high performance communications devices. Elimination of redundant components, functions, or circuitry is highly desired in communication electronics, as is increased performance without increasing device size or weight. Further, there is a continuing need for reliable and quality signal transfer, improved transmitter-receiver isolation, and very high Q value circuitry with respect to duplexers. In addition, further considerations include polarization, tradeoffs between isolation and size, tuning precision, and transmit/receive frequency spacing for a given band versus wholesale tuning between bands.